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Map of the study area. a The location of Bihar State in India. b The location of Vaishali District among the other VL endemic districts in Bihar. c The spatial distribution of the 16 Vaishali blocks and the villages boundary within them
Source publication
Abstract Background Visceral leishmaniasis (VL) in Bihar State (India) continues to be endemic, despite the existence of effective treatment and a vector control program to control disease morbidity. A clear understanding of spatio-temporal distribution of VL may improve surveillance and control implementation. This study explored the trends in spa...
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Background: Brazil concentrates 96% of visceral leishmaniasis cases occurred in Americas, and Maranhão is the Brazilian state with the highest number of registered cases. We aimed to analyze the spatio-temporal dynamics of visceral leishmaniasis transmission in a Brazilian region with high endemicity between 2009 to 2017. Methods: We carried out an...
Citations
... However, the study neither considered any risk factors to identify the clusters nor to forecast incidence [28]. In India, analyses of the association of VL incidence with climatic factors, and vector density have been done but are mostly limited to small geographical areas [9,[29][30][31]. The studies focused towards identifying drivers of hotspots at the village or household level [9,30,31]. ...
... In India, analyses of the association of VL incidence with climatic factors, and vector density have been done but are mostly limited to small geographical areas [9,[29][30][31]. The studies focused towards identifying drivers of hotspots at the village or household level [9,30,31]. Deb et al. [7], applied a negative binomial regression model to the state level annual VL incidence data from Bihar and showed significant negative associations of VL incidence with maximum temperature, and average temperature. Bhunia et al. [29], analyzed district level VL incidence data and observed VL incidence in the Gangetic plain of Bihar is positively associated with environmental (presence of water bodies, woodland and urban, built-up areas, soil type) and climatic (air temperature, relative humidity and annual rainfall) factors. ...
Background
As of 2021, the National Kala-azar Elimination Programme (NKAEP) in India has achieved visceral leishmaniasis (VL) elimination (<1 case / 10,000 population/year per block) in 625 of the 633 endemic blocks (subdistricts) in four states. The programme needs to sustain this achievement and target interventions in the remaining blocks to achieve the WHO 2030 target of VL elimination as a public health problem. An effective tool to analyse programme data and predict/ forecast the spatial and temporal trends of VL incidence, elimination threshold, and risk of resurgence will be of use to the programme management at this juncture.
Methodology/principal findings
We employed spatiotemporal models incorporating environment, climatic and demographic factors as covariates to describe monthly VL cases for 8-years (2013–2020) in 491 and 27 endemic and non-endemic blocks of Bihar and Jharkhand states. We fitted 37 models of spatial, temporal, and spatiotemporal interaction random effects with covariates to monthly VL cases for 6-years (2013–2018, training data) using Bayesian inference via Integrated Nested Laplace Approximation (INLA) approach. The best-fitting model was selected based on deviance information criterion (DIC) and Watanabe-Akaike Information Criterion (WAIC) and was validated with monthly cases for 2019–2020 (test data). The model could describe observed spatial and temporal patterns of VL incidence in the two states with widely differing incidence trajectories, with >93% and 99% coverage probability (proportion of observations falling inside 95% Bayesian credible interval for the predicted number of VL cases per month) during the training and testing periods. PIT (probability integral transform) histograms confirmed consistency between prediction and observation for the test period. Forecasting for 2021–2023 showed that the annual VL incidence is likely to exceed elimination threshold in 16–18 blocks in 4 districts of Jharkhand and 33–38 blocks in 10 districts of Bihar. The risk of VL in non-endemic neighbouring blocks of both Bihar and Jharkhand are less than 0.5 during the training and test periods, and for 2021–2023, the probability that the risk greater than 1 is negligible (P<0.1). Fitted model showed that VL occurrence was positively associated with mean temperature, minimum temperature, enhanced vegetation index, precipitation, and isothermality, and negatively with maximum temperature, land surface temperature, soil moisture and population density.
Conclusions/significance
The spatiotemporal model incorporating environmental, bioclimatic, and demographic factors demonstrated that the KAMIS database of the national programmme can be used for block level predictions of long-term spatial and temporal trends in VL incidence and risk of outbreak / resurgence in endemic and non-endemic settings. The database integrated with the modelling framework and a dashboard facility can facilitate such analysis and predictions. This could aid the programme to monitor progress of VL elimination at least one-year ahead, assess risk of resurgence or outbreak in post-elimination settings, and implement timely and targeted interventions or preventive measures so that the NKAEP meet the target of achieving elimination by 2030.
... The disease is spreading, and new VL foci are now being reported in different regions of Ethiopia 29 . Because VL infection differs by geographical context and population, the control strategy must be according to the local epidemiology of each place 35 . The majority of VL cases found in this study were from Waghemra zone's poorest areas or districts, such as Abergele, Sehala, and Ziquala. ...
Abstract Visceral leishmaniasis is a major, life-threatening parasitic disease that still remains a serious public health problem in Ethiopia. Understanding the epidemiological, clinical, and hematological profiles of visceral leishmaniasis patients is important for implementing evidence-based control strategies. It is also important for early treatment and to decrease the mortality rate from the disease. Therefore, this study was aimed at assessing the epidemiological, clinical, and hematological profiles of visceral leishmaniasis among patients visiting Tefera Hailu Memorial Hospital, Northeast Ethiopia. A retrospective study was conducted at Tefera Hailu Memorial Hospital from September 2017 to August 2021. Data were collected from the medical records of suspected patients who were tested by the rK39 rapid diagnostic by strictly following standard operating procedures. The data was summarized using Microsoft Excel and analyzed using SPSS 26 version software. Descriptive statistics were used to describe the epidemiological, clinical, and hematological profiles of visceral leishmaniasis patients. A p-value
... However, the most commonly used term is Kala azar, which in Hindi means black sickness or black fever. The terms originally referred to Indian Visceral Leishmaniasis due to its characteristic symptoms, blackening or darkening of the skin of the hands, feet, face and the abdomen (Mandal et al., 2018;Azim et al., 2021). ...
... The majority of cases (~ 73%) are found in 10 districts, including Araria, East Champaran, Gopalganj, Muzaffarpur, Purnia, Siwan, Saharsa, Sitamarhi, and Darbhanga (NVBDCP-2017). A total of 12,000 villages were affected over 458 blocks, putting 99 million people at risk (Mandal et al., 2018). There has been some level of elimination for these blocks with 86% achievement rate. ...
Visceral leishmaniasis or Kala-azar is a vector-borne disease caused by an intracellular parasite of the genus leishmania. In India, Amphotericin B (AmB) is a first-line medication for treating leishmaniasis. After a large-scale resistance to pentavalent antimony therapy developed in Bihar state, it was rediscovered as an effective treatment for Leishmania donovani infection. AmB which binds to the ergosterol of protozoan cells causes a change in membrane integrity resulting in ions leakage, and ultimately leading to cell death. The treatment effect of liposomal AmB can be seen more quickly than deoxycholate AmB because, it has some toxic effects, but liposomal AmB is significantly less toxic. Evidence from studies suggested that ABLC (Abelcet) and ABCD (Amphotec) are as effective as L-AmB but Liposomal form (Ambisome) is a more widely accepted treatment option than conventional ones. Nevertheless, the world needs some way more efficient antileishmanial drugs that are less toxic and less expensive for people living with parasitic infections caused by Leishmania. So, academics, researchers, and sponsors need to focus on finding such drugs. This review provides a summary of the chemical, pharmacokinetic, drug-target interactions, stability, dose efficacy, and many other characteristics of the AmB and their various formulations. We have also highlighted the clinically significant aspects of PKDL and VL co-infection with HIV/TB.
... India alone accounts for more than 80% of the total VL cases in the Indian subcontinent (WHO 2015). In India, VL is endemic in the eastern states of Bihar, West Bengal, Jharkhand and Uttar Pradesh, where around 130 million people are at risk (Mandal et al. 2018). Another manifestation, post-kala-azar dermal leishmaniasis (PKDL) is a dermal sequel of apparently cured VL (WHO 2019). ...
L. donovani is an intracellular protozoan parasite, that causes visceral leishmaniasis (VL), and consequently, post-kala azar dermal leishmaniasis (PKDL). Diagnosis and treatment of leishmaniasis is crucial for decreasing its transmission. Various diagnostic techniques like microscopy, enzyme-linked immunosorbent assays (ELISA) and PCR-based methods are used to detect leishmaniasis infection. More recently, loop-mediated isothermal amplification (LAMP) assay has emerged as an ideal diagnostic measure for leishmaniasis, primarily due to its accuracy, speed and simplicity. However, point-of-care diagnosis is still not been tested with the LAMP assay. We have developed a portable LAMP device for the monitoring of Leishmania infection. The LAMP assay performed using our device can detect and amplify as little as 100 femtograms of L. donovani DNA. In a preliminary study, we have shown that the device can also amplify L. donovani DNA present in VL and PKDL patient samples with high sensitivity (100%), specificity (98%) and accuracy (99%), and can be used both for diagnostic and prognostic analysis. To our knowledge, this is the first report to describe the development and application of a portable LAMP device which has the potential to evolve as a point-of-care diagnostic and prognostic tool for Leishmania infections in future.
... year, 1.5 million new cases of CL [5,8] and 20,000 to 40,000 deaths due to this disease occur. [9,10]. ...
Background
Cutaneous leishmaniasis (CL) is endemic in 98 countries, and 350 million people are at risk of the disease worldwide. In endemic areas, conducting educational interventions is necessary to change preventive behaviors of CL. This study aimed to investigate the effect of an educational intervention based on the BASNEF model on CL preventive behavior in students.
Methods
The present quasi-experimental study examined 80 students living in endemic areas of leishmaniasis in Isfahan province, Iran based on the BASNEF model. The required data were collected twice before and two months after the educational intervention based on a questionnaire whose validity and reliability had been already proven in other studies. The intervention was performed in three educational sessions for the students in the intervention group and 1 educational session for teachers and parents. Data were analyzed by SPSS (VER26) using the chi-square test, independent t-test, analysis of covariance (ANCOVA), and Paired t-test.
Results
After intervention, the mean scores of Knowledge (P < 0.001), attitude (P = 0.02), subjective norms (P = 0.04), behavioral intention (P < 0.001), and behavior (P = 0.02) indicated significant differences between the intervention and control groups, but an increase in mean scores of enabling factors was not significant (P = 0. 93).
Conclusions
Providing students with the educational intervention based on the BASNEF model improve their ability to the extent that they transmit these educations to their family members, which would be effective in preventing and controlling CL in leishmaniasis-prone areas.
Trial registration
Name: Iranian Registry of Clinical Trials. Registration number: IRCT20201024049131N1. Registration date: 2020–11-20. Registration timing: prospective.
... It is also notable that Isfahan province is one of the most important focus of CL in Iran. Despite the new diagnosis and treatments of leishmaniasis, it is still considered a serious public health concern particularly in developing countries including Iran and has an economic burden on health resources (Rasti et al. 2018, Norouzinezhad et al. 2016, Jafari et al. 2020, Mandal et al. 2018, Glans et al. 2018. ...
... The results were consistent with the main results of other studies. It also consistent with the leishmaniasis incubation period because the most mosquito bites occur every year from early September to early November (Hatami et al. 2018;Khajehdalluei et al. 2014;Mandal et al. 2018). ...
Cutaneous leishmaniasis (CL) is a vector-borne infectious disease that is affected by various environmental agents. The main objective of this study was to determine the spatial distribution of CL incidence by using Geographical Information System (GIS). This is a cross-sectional study that was conducted during 5 years from 2014 to 2018 in Isfahan, Iran. We used the required data on each leishmaniasis patient that were recorded from 44 counties of Isfahan in the databases and archive of the Provincial Health Centre. We used GIS for determining the incidence of CL in the high-risk foci. Moran index was used to identify high risk points (clustering in similar values) compared to the values of neighborhood points. Hot spot analysis was conducted by Getis-Ord-Gi. The highest incidence of the disease occurred in the age group of 18–64 years and 61.6% of patients were male. According to seasonal distribution, autumn (58.6%) had the highest frequency. Time trend of incidence showed that it had both decreasing and increasing, and there was a sudden upward trend of disease in 2018 except only two counties. The hot spots were involved the central areas of the Isfahan province slightly toward to the north and southeast of the province. Moran index showed that the differences for all points were not significant (p-value>0.05). Varzaneh (placed in southeast of Isfahan) was the hottest spot and had the worst position for leishmaniasis compared to all years and all cities.
... In addition, there are reports of outbreaks in low-and non-endemic zones. [1][2][3] Treatment of VL relies mainly on pentavalent antimonials, amphotericin B, liposomal amphotericin B, miltefosine, paromomycin or their combinations. 4 The limitations of present chemotherapeutics include toxicity, noncompliance, prolonged and a cumbersome regimen that is unaffordable to the rural population, increasing antimonial resistance, complications of post kala-azar dermal leishmaniasis (PKDL), and HIV-coinfections. ...
Introduction
The current therapeutic armory for visceral leishmaniasis (VL) caused by Leishmania donovani complex is inadequate, coupled with serious limitations. Combination therapy has proved ineffective due to mounting resistance; however, the search for safe and effective drugs is desirable, in the absence of any vaccine. There is a growing interest in the application of nanoparticles for the therapeutic effectiveness of leishmaniasis. Aimed in this direction, we assessed the antileishmanial effect of gold nanoparticles (GNP) against L. donovani in vitro.
Methods
GNP were synthesized and characterized for particle size by dynamic light scattering (DLS) and atomic force microscopy (AFM) and for optical properties by UV-visible spectroscopy. Cytotoxicity of GNP was measured by the MTT proliferation assay. The antileishmanial activity of the nanoparticles was evaluated against L. donovani promastigotes and macrophage-infected amastigotes in vitro.
Results
GNP showed a strong SPR peak at 520 nm and mean particle size, polydispersity index (PDI), and zeta potential of 56.0 ± 10 nm, 0.3 ± 0.1 and −27.0 ± 3 mV, respectively. The GNPs were smooth and spherical with a mean particle diameter of 20 ± 5 nm. Nanoparticles [1.2–100 µM] did not reveal any cytotoxicity on RAW 264.7 murine macrophage cell line, but exerted significant activity against both promastigotes and amastigote stages of L. donovani with 50% inhibitory concentrations (IC50) of 18.4 ± 0.4 µM and 5.0 ± 0.3 µM, respectively. GNP showed significant antileishmanial activity with deformed morphology of parasites and the least number of surviving promastigotes after growth reversibility analysis.
Conclusion
GNP may provide a platform to conjugate antileishmanial drugs onto the surface of nanoparticles to enhance their therapeutic effectiveness against VL. Further work is warranted, involving more in-depth mechanistic studies and in vivo investigations.
... GPS has been used for systematic and reconnaissance field survey [39], and subsequently, data were pooled in to the Geographic Information Systems (GIS) platform to organize, create thematic layers of maps [3][4][5][6][7][8][9], and to analyze the spatial and temporal aspects of mosquito breeding habitats [5,8,10,14,15] and predict the hot spot regions of VBD epidemics [52,54,55] leads to control disease epidemics [23,24,35]. Multispectral and multi-temporal remote sensing data were used for analyzing the longitudinal variations in immature vector abundance [3,5,63,65]. The integrated remote sensing and GPS has been utilized for mapping of vector abundance in various seasons with respect to space and time. ...
... Filariasis vector mosquitoes are found ubiquitous and abundance in the entire region of the country [50], however, the disease endemic regions are associated with landscape, soils, and human urban settlements [51]. The environmental variables corresponding to leishmaniasis vector breeding specific ground characteristics were studied and demarcated the risk borne areas for both visceral leishmaniasis and cutaneous leishmaniasis based on the breeding landscapes [58][59][60][61][62][63][64][65][66][67][68][69][70][71][72], settlement housing structures and roof types, soil type's water holding capacity, alkaline and salinity, and crop types [58][59][60][61][62][63][64][65][66][67][68][69][70][71][72]. These bio-geo environmental variables have been included in the spatial and ecological niche modeling [64,70,71,72] process, and thus, geo-spatial and ecological niche models were developed [64,70,71,72] for forecasting leishmaniasis transmission risk using remote sensing and GIS [70,71,72]. ...
... Filariasis vector mosquitoes are found ubiquitous and abundance in the entire region of the country [50], however, the disease endemic regions are associated with landscape, soils, and human urban settlements [51]. The environmental variables corresponding to leishmaniasis vector breeding specific ground characteristics were studied and demarcated the risk borne areas for both visceral leishmaniasis and cutaneous leishmaniasis based on the breeding landscapes [58][59][60][61][62][63][64][65][66][67][68][69][70][71][72], settlement housing structures and roof types, soil type's water holding capacity, alkaline and salinity, and crop types [58][59][60][61][62][63][64][65][66][67][68][69][70][71][72]. These bio-geo environmental variables have been included in the spatial and ecological niche modeling [64,70,71,72] process, and thus, geo-spatial and ecological niche models were developed [64,70,71,72] for forecasting leishmaniasis transmission risk using remote sensing and GIS [70,71,72]. ...
The vector borne disease (VBD) epidemics trend have been gradually increased in the world, especially in India for several decades. Mapping the vector breeding habitats, spatial distribution and seasonal variation of vector density, epidemiological survey, and mapping the thematic layers of bio-geo-environmental risk variables, VBD occurrences with respect to space and time, disease surveillance, spatial analysis and spatial modeling for prediction of epidemic risk assessment, and forecast are herculean task, and are involved huge expenditure, man power, and long duration, by the time, then the situation would have been changed, whereas, remote sensing, GPS and GIS are the finest technology which have been used for achieving the task in time with high accuracy, reliable, and low cost. The earth environmental remote sensing of multispectral satellite data are readily available to process the past and present condition of the vector ecology based on the data derived from visible to Infrared (Near Infrared, Middle Infrared, Infrared, and Thermal infrared) i.e. 0.0.45 µm-0.52 µm (Blue), 0.52 µm-0.60 µm (Green), 0.63 µm-0.69 µm (Red), 0.76 µm-0.90 µm (NIR), 1.55 µm-1.75 µm (Infrared), Thermal IR bands 10.41 µm-12.5 µm, and 2.08 µm-2.35 µm, and spatial resolution ranging from 30 meters to less than 1 meters, and SAR (Synthetic Aperture Radar), AVHRR (Advanced Very High Resolution Radiometer), MWR (Microwave Radiometer), microwave remote sensing of various earth resource satellites have been used for the study of weather parameters and climate determinants, and were used to analyze spatial topology with vector abundance and VBD epidemics. The results could thus provide a new basis of guidelines for the control of mosquito vectors as well as disease epidemics early in advance. Mostly, the situation, when the diseases occurrences are strongly related to geo-ecological risk variables, viz; weather parameters, climate season, agriculture, vegetation, land-use / land cover, water features, and physiographic landscapes, and therefore, the data pertaining to bio-geo environmental variables have been included in the spatial prediction models. Remote sensing, and GPS have been used for data collection of vector data (mature and immature), epidemiological site specific information, geo-environmental parameters, and vectors breeding habitats, subsequently, GIS have been used to analyze and mapping epidemic hotspots of VBD based on climate determinants are provided the key elements for depicting thematic layers concerned in both the vector control, prevention measures, and epidemiological management processes in advance.
... The use of this approach in studies concerning spatiotemporal analysis of infectious neglected diseases has increased in recent years. Using univariate GMI and LMI have shown that several diseases present cluster distribution patterns including hotspots (Machado et al., 2017;Osei & Stein, 2017;Mandal et al., 2018;Salimi et al., 2018;Tewara et al., 2018;Alene et al., 2019;Nuñez-González et al., 2019;Okunlola et al., 2019;Vivaldini et al., 2019). Bivariate GMI and LMI have only been applied to evaluate spatial autocorrelation and clusters In relation to triatomines, T. cruzi and Chagas disease, spatial autocorrelation by Moran's I has not been used frequently. ...
Trypanosoma cruzi requires a triatomine insect vector for its life cycle, which can be complex in different enzootic scenarios, one of which is the unique transmission network in the Atlantic Forest of south-eastern Brazil. In the state of Espírito Santo, highly infected Triatoma vitticeps are frequently reported invading domiciles. However, triatomines were not found colonizing residences in this state and mammals in the surrounding areas did not present T. cruzi infection. To date, the biotic and abiotic variables that modulate T. vitticeps occurrence and T. cruzi infection in Espírito Santo are still unknown. The aim of this study was to identify the environmental variables that modulate their occurrence. Local thematic maps were generated for two response variables: T. vitticeps occurrence and T. cruzi infection. The following explanatory variables were tested: climate (temperature, relative air humidity and rainfall), altitude, mammalian species richness as well as soil and vegetation types. Spatiotemporal distribution patterns and correlation levels between response and explanatory variables were assessed through spatial statistics and map algebra modelling. The central and southern mesoregions presented higher T. vitticeps and T. cruzi distributions and can be considered transmission hotspots. The explanatory variables that explained these phenomena were relative air humidity, average temperature, soil type, altitude and mammalian species richness. Algebra map modelling demonstrated that central and southern mesoregions presented the environmental conditions needed for T. vitticeps occurrence and T. cruzi infection.
